Imprevid Triftfi of Bleaching, t<j | 



Eypenmetit IX. A repetition of Experiment VIII. The colour of 385 grains of the de- 

 codlion was deftroyed in this experiment, 



Experiment X. To half an ounce of the acid fix drops of the liquid alicali were added. 

 This mixture deftroyed the colour of 315 grains of the deco<flion. 



Experiment XI. Eight drops of the alkali were mixed with half an ounce of the acid. 

 This mixture deftroyed the colour of 305 grains of the decoction. 



On a comparative view cf the refults of thefe experiments, it will appear that an addition 

 of potafli to the bleaching liquor impairs its ftrength confiderably. This diminution of power 

 and the expence of potafti are a ferious lofs in an extenfive manufadlure. It would there- 

 fore be defirable to have an apparatus for the ufe of the pure oxygenated muriatic acid fimply 

 dificilved in water, which is at once the cheapeft and beft vehicle for it. This apparatus muft 

 be fimple in its conftruflion, and obtained at a moderate e.xpence ; it muft: confine the 

 liquor in fuch a manner as to prevent the efcape of the oxygenated muriatic acid gas, which 

 is not only a lofs of power, but alfo an inconvenience to the workmen and dangerous to their 

 health; and it muft at the fame time be fo contrived, that every part of the ftufF which is 

 confined in it fhall certainly and nece/Tarily be expofed to the aftion of the liquor in regular 

 fiicceflion. Having invented an apparatus capable of fulfilling all thefe conditions, I have 

 the pleafure of fubmitting a defcription of it to the Society by means of the annexed drawing. 



Explanation of Plate XI. 



Fig. I, is a fe£lion of the apparatus. It confifts of an oblong deal ciftern, A BCD, 

 made water-tight. A rib, E E, of afh or beech wood, is firmly fixed to the middle of the 

 bottom CD, being mortifed into the ends of the ciftern. This rib is provided with holes 

 at F F, in which two perpendicular axes are to turn. The lid, A B, has a rim G G which 

 finks and fits into the ciftern. Two tubes H H are fixed in the lid, their centres being 

 perpendicular over the centres of the fockets F, F, when the lid is upon the ciftern. At I, 

 is a tube by which the liquor is introduced into the apparatus. As it is neceftary that the 

 fpace within the rim G G be air-tight, its joints to the lid and the joints of the tubes muft be 

 very clofe, and, if neceflary, fecured with pitch. , Two perpendicular axes, K, L, made of afh 

 or beech wood, pafs through the tubes H, H, and reft in the fockets, F, F. A piece of ftrong 

 canvas, M, is fewed very tight round the axis K, one end of it projecting from the axis. 

 Ihe other axis, is provided with a fimiljr piece of canvas. N, are pieces of cloth rolled upon 

 the axis L. Two plain pulleys, O, O, are fixed to the axes in order to prevent the cloth fron> 

 flipping down. The (hafts are turned by a moveable handle P. Q,, a moveable pulley, 

 round which pafl'es the cord R. This cord, which is faftened on the oppofite fide of the lid 

 ffee fig. 2) and paffes over the fmall pulley S, produces friftion by means of the weight T» 

 By the fpigot and fauffet V, the liquor is let off when exhaufted. 



Fig. 2. A plan of the apparatus with the lid taken off. 



The Manner of ujing the Apparatus^ 

 The dimenfions of this apparatus are calculated for the purpofe of bleaching twelve or 

 fifteen pieces of 4- 4. calicoes, or any other fluffs of equal breadth and fubftance. When the 

 goods are ready for bleaching, the axis L is placed on a frame in a horizontal pofition,, and 

 one of the pieces N being fattened to the canvas M, by means of wooden (kcwers in the man- 

 aer reprefcnted in fig. 1, it is rolled upon the axis by turning it with the handle P. This 



6 operation 



